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Alan’s Lab - current topic: UberEnvironment 2 Lighting Rig
Posted: 25 October 2012 12:02 PM   [ Ignore ]   [ # 16 ]
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Cool—- glad to be of help!  Feel free to chime in here with questions, suggestions, and suchlike, as I fumble around in the dark—- er, make that, fumble around with a

Starter UberEnvironment 2 Lighting Rig . . . [Yay, new page!]

First, a pointer to my favorite thread on the topic, adamr001’s “Learning UberEnvironment 2…”  Very useful.
[EDIT] Also see a Dreamlight3D sample tutorial/introduction for UE2.

Second, a quick textual run-through of some UE2 settings that would be typical of my usage.  Your mileage will vary, you’ll prioritize different attributes, and I’ll even be adjusting them slightly/wildly as I work through test renders here.  So stay flexible!

Basic:

Intensity - 100%
Intensity Scale - 100% . . . . . . .  For starters. This is a multiplier for the preceding attribute.
  (You might use this for a “noir” effect, to let you leave the first one bright enough so you can see
    your scene in the preview, and then dial this down so the actual render has darker shadows.)
Color - [255 247 221] . . . . . . . . . I think I want to go just a smidgen warm with this light.
        & OmKitchen_EnvM.jpg . . . From DS4 Pro’s Library\Runtime\textures\omnifreaker\Environment folder.
Environment Mode - Occlusion w/Soft Shadows . . . A good middle choice. Nice effect, but not too computationally expensive.

Map Controls:

Saturation - 100%
Contrast - 100% . . . Starting with defaults here. Similar to functions in an image editor, but here
                              they’re affecting the color and bright/dark areas of your ambient light pattern.
                              This’ll make more sense with demo images later.

Ray Tracing:

Occlusion Strength - 75% . . . . . . . . How intense or dark you want the Ambient Occlusion shadow effect to be.
                                                      In most scenes I de-intensify it somewhat; this is a good starter value.
Indirect Lighting Strength - 100% . . . Default.  How strong you want the Indirect Lighting effect (bounce light) to be.
                                                      Not used with the two “Ambient Occlusion” modes of UE2.
                                                      [Above 2 notes edited after clarification from Szark—thx!]
Occlusion Color - [37 34 43] . . . . . . Something (ANYTHING!) other than that fleshtone-deadening pure black,
                                                      in the Ambient Occlusion shadow effect.  Purple is kinda classical. ;^D*
Occlusion Samples - 96 . . . . . . . . . Affects quality; higher generally means less “freckling” in the A.O. shadows.
                                                      Not terribly computationally expensive, even on my old obsolete PC.
                                                      It’s reputed to be better to stick with integer powers of 2 here—- 64, 32, 16, etc.
                                                      96 provides preview renders that I find easier to gauge than 64 does,
                                                      while being faster enough than 128 to be worthwhile.
                                                      [Thanks once more go to Szark for this note.]

Advanced:

Shadow Bias - 0.10 . . . . . . . . . . . . Default value.  Offsets any cast shadows a bit. (!)  Yeah, bizarre, but it’s needed for virtual lights.
                                                      Otherwise you get shadows sticking through what’s casting them, or some such weirdness.
Shading Rate - 8 . . . . . . . . . . . . . . Another quality setting; lower number, better quality, longer render time.
Max Error - 0.10 . . . . . . . . . . . . . . And another quality setting; lower number, better quality, longer render time.
Maximum Trace Distance - 500 . . . Default value.  How close two surfaces have to be to cause A.O. shadows on each other.


Phew!  Off to set up a test scene…

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Posted: 25 October 2012 08:39 PM   [ Ignore ]   [ # 17 ]
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Okay, so here’s a render with just an UberEnvironment light active.  I reused an existing scene, moved a few props around, added a couple of others, and then went through with a virtual spraypaint can, turning most of the surfaces off-white.  For some reason, that last part was ridiculously fun…

Changes to the settings quoted above, mostly for exaggerated effects:

Turned the Intensity Scale down to 62.5%, to avoid an overexposed effect.
The environment map is OmKHPark_EnvM.jpg, from the same location.
(The kitchen didn’t have much color variation—- brown floor, mostly.)
Cranked the map Saturation up to 125%, to exaggerate the color of the simulated Ambient light.
Turned Occlusion Strength down to 75%, for dimmer shadows.
Turned Indirect Lighting Strength up to 125%, to exaggerate the color of the Ambient light. [Echo in here?]

The thing hovering behind her left shoulder is the EnvironmentSphere, which loads in parented to the UberEnvironment2 light.  Normally it’s huge—- the idea being to show you the simulated environment that’s bouncing all this light inward.  Personally, I find it more useful to shrink it down and look at it from the outside—- that way, if I turn the UE2 light so that, say, a red area of this preview sphere is facing the camera, then I know that surfaces in the scene that are facing the camera will receive reddish ambient light.  If I look at it from the inside, I’m looking at the light colors for stuff facing AWAY from the camera.  Not as useful, IMO.

It also took a bit of finagling to get the EnvironmentSphere to show up in the render—- it’s set up not to. smile

So anyway, if you click through to the (slightly) larger and (much) clearer original render, you can see that upward-facing surfaces are receiving blue ambient light from the virtual sky, while downward-facing (and sideways) surfaces are picking up the green of the virtual lawn.

Next test (probably tomorrow): add an ordinary DAZ Studio spotlight.

Alan

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Posted: 25 October 2012 09:12 PM   [ Ignore ]   [ # 18 ]
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Okay, now that I understood. Sphere image = Lighting. I got a Click moment. Thank You. Very Simple post (mine) but It covers the Idea I think.

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Posted: 26 October 2012 06:04 AM   [ Ignore ]   [ # 19 ]
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You’re entirely welcome!  And yes, you do Brief Yet Clear very well.  Whereas I keep giving myself awkward reminders on why I’m not a writer… tongue rolleye

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Posted: 26 October 2012 06:43 AM   [ Ignore ]   [ # 20 ]
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Here’s the scene with an overhead(-ish) spotlight switched on.

The spotlight is using a cool [221 238 255] color, in keeping with the color scheme of the OmKHPark_EnvM.jpg environment map.  Its intensity is a mere 37.5%, and the UE2 light’s Intensity Scale multiplier is also lowered, to 50%.  That’s due to the fact that, on my first try, much of the white area was “blown out.”  Have I mentioned that there’s a LOT of white area in this set?  I still managed to blow out the highlights a bit on the second try—- however, that seemed to harmonize with the illicitly displayed EnvironmentSphere, so I left it like that.

This is my go-to lighting rig—- an UberEnvironment2 set to do image-based Ambient Occlusion, plus one key light—- when starting to light a scene.  From here, I can add elaborations, but this gets a big hunk of the heavy lifting done in a 3Delight render, for not much processing-time penalty.  (And given the low probability of faster hardware in my immediate future, this is significant.)  If you flip between this render and the previous one, you can see that the modeling (in the lighting sense of the word) of forms in the shadow areas is due to the UE2 light.  Much nicer than an inky void under the tabletop.  (Unless that’s what the image calls for, of course.)

Another UE2 tip that’s perhaps overly obvious, but still worth mentioning: you can rotate the light, to change how the image-based simulated Ambient light falls on your scene.  Here it’s rotated -30 on the Y axis, to bring the sunny hotspot to the front.  I’ll be back with a quick demo render or two in a bit, to show what silliness this allows…

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Posted: 26 October 2012 06:59 AM   [ Ignore ]   [ # 21 ]
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Let’s see… There’s a dark green leafy canopy overhead, and a nearby swimming pool is reflecting some blue light upward.  Yeah, that must be it… tongue wink

(UE2 rotations: X 90, Y -72, Z 120.)

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Posted: 26 October 2012 08:41 AM   [ Ignore ]   [ # 22 ]
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Okay, I’ll stop soon. raspberry

Venturing perilously close to psychedelic territory, here are a couple of renders using the lighting setup from my contribution to the Halloween Freebies Challenge.  Still one UE2 and one spotlight.  The second one (if I’ve got my attachments in a row) is even shot through the same camera.

Besides being silly, this also demonstrates how the surface settings affect the mood achievable by the lighting.  All that clinical white is a lot less gothic than a dark-ish, heath-colored ground plane…

The environment map image is OmCornellBox_EnvM.jpg; UE2 rotations are X -45, Y -54, and Z 18; Contrast (under Map Controls) is down to 75%; Occlusion Strength is up to 87.5%, for more intense (darker) occlusion shadows.

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testUE2_B1h.pngtestUE2_B1.png
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Posted: 27 October 2012 08:00 PM   [ Ignore ]   [ # 23 ]
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One more comparison shot.  At the insistence of the image attachment feature here, on the left is “Indirect Lighting w/Soft Shadows,” and on the right is “Occlusion w/Soft Shadows.”  The intensities of both the UE2 light and the spotlight on the Occlusion render are 50%, as opposed to 41.7% on the Indirect Lighting render—- that extra brightness was needed to get the overall values roughly the same.

Basically, with the Indirect Lighting setting, UE2 does all the math it does for the Occlusion setting, plus it calculates bounce light.  While a detectable trace of the green and the orange of those two bowls have thereby been reflected into their respective shadows, by far the dominant difference between the two renders is the upward bounce from all that white.  It’s especially visible in the yellow portion of the abstract sculpture, in its contour shadow.

Definitely improved plausibility, but not without its cost: the render times here went from under 5 minutes to nearly 2 hours. excaim

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Posted: 01 November 2012 04:16 PM   [ Ignore ]   [ # 24 ]
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Just to clairify a few things.

Having the Indirect Lighting Strength at 125% without using Indirect Lighting functuon in UE2 is a waste of time. You can set to to 1000% but without IDL selected it isn’t going to do anything.

Saturation effects the light colour of the HDRI map produces. So if the light colour is too strong then lowering it will lessen the colour.
Occlusion Strength is better at 75%
Occlusion Samples: best to keep at either 64 or 128. I read somewhere that we should stick to the math that 3Delight uses. 8,16,32,64,128 you see the pattern. I am not sure if this has changed with the new 3Delight Render engine we have now in DS4.5.1.6

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Posted: 01 November 2012 04:54 PM   [ Ignore ]   [ # 25 ]
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Szark - 01 November 2012 04:16 PM

Just to clairify a few things.

Having the Indirect Lighting Strength at 125% without using Indirect Lighting functuon in UE2 is a waste of time. You can set to to 1000% but without IDL selected it isn’t going to do anything.

Saturation effects the light colour of the HDRI map produces. So if the light colour is too strong then lowering it will lessen the colour.
Occlusion Strength is better at 75%
Occlusion Samples: best to keep at either 64 or 128. I read somewhere that we should stick to the math that 3Delight uses. 8,16,32,64,128 you see the pattern. I am not sure if this has changed with the new 3Delight Render engine we have now in DS4.5.1.6

Nice clarification & expansion—thanks!

Yeah, now that you point it out, the lexical connection between IDL & IDL Strength seems kinda obvious.  I’ll run a couple of quick tests to verify, but I expect you’re correct. [EDIT: Yes, it checks out—correction on its way…]

Yep, that observation agrees with my experience with Saturation.  More often I’m turning it up for exaggerated effect. :D

Occlusion Strength at 75% matches up with my followup post, immediately after the text dump.  Checked a few of my old scenes, and although it’s not always that exact value, I do tend to attenuate it some.  Good point.

The integer powers of 2 thing is interesting.  I seem to recall seeing some visible decrease in speckling as I crank it up through the intermediate values (which would be fractional powers of 2), but there’s also mathematical efficiency to consider.  I wonder if the render times take a hit with those—i.e., it’s possible that there’s logic in the code to use more efficient bit-shift math when the Samples value is an integer power of 2.

If you get a chance, could you delete the quote from your post?  I expect I’ll have a few notes to add to the original.  rolleyes

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Posted: 01 November 2012 05:07 PM   [ Ignore ]   [ # 26 ]
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The integer (nice word couldn’t think of it myself) I am not 100% sure of this so I need to ask the more geekish CV’s. smile

I am so glad you took this in the spirit it was given.

I have noticed a few things about Ubersurface too that needs a bit more clarification but more on that later.It is getting close to bed time for me.

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Posted: 01 November 2012 05:24 PM   [ Ignore ]   [ # 27 ]
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Powers of two work better because the PC is based on the Binary system. All Powers of two are BASE powers that the Processors can read without doing any math. That was my understanding when I took Microprocessor design at R.E.T.S. twenty odd years ago. Now that the Systems can read 128 bits and more in one go I’m not sure that still applies. I was in it at 8 bit systems.

Just my two cents.

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Posted: 01 November 2012 06:30 PM   [ Ignore ]   [ # 28 ]
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Interesting Jad. I wonder if that is still the case. I have asked in our corner of the forum about this. We need to give it a few days for other CV’s to see it.

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Posted: 01 November 2012 08:54 PM   [ Ignore ]   [ # 29 ]
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I just did a rough, unscientific set of time trials—- being in the middle of accreting a new scene out of pieces of old ones, I had a reasonably simple (but not too simple) surreal jumble of props & one figure, with a fair number of surfaces occluding each other.  So I did a series of quick renders, stepping the Occlusion Sample slider from 16 to 128, in increments of 16.

Note that this left a bunch of variables uncontrolled, especially available memory as render windows piled up.  On the other hand, they’re small renders, and this situation is similar to my ordinary working conditions, so I’m not too concerned by this for a quick test.

Times (approx): 46s ; 1m 1s ; 1m 19s ; 1m 31s ; 1m 47s ; 2m 2s ; 2m 17s ; 2m 34s
Deltas (approx):    15s       18s         12s         16s         15s       15s       17s

Despite that slight dip to a 12 seconds delta when going from 48 to 64, this is close enough to a linear progression that I feel comfortable in assuming that there’s not a big hit (if any) using values that are not integer powers of 2.  Heck, Omnifreaker could have programmed his shader/light code so this slider went in integers from 1 to 7, and then used those values as exponents.  Since, however, the intermediate values were made available, I’m guessing that they’re there to be used, if desired.

A proper test would require trying many more scenes, preferably from multiple authors, and many more intermediate values.  Which would be way beyond the scope of a series of posts based on, “Hey, here are some starter values that give me a reasonable result, so if you’re stuck on UE2, or not even trying it, here’s a place you can start, and then tweak settings to your own taste.”

So, I think I’ll reinstate my 96, while keeping the new note beneath it.  It’s faster than 128, but still “de-freckled” enough, compared to 64, to allow me to judge how dark-to-medium-light surfaces (like skintones) are going to respond in a final render.

Good discussion, folks!  I do appreciate the help in livening the thread up, and coming up with interesting things to try.  Thanks!

g’night
Alan

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Posted: 03 November 2012 04:40 AM   [ Ignore ]   [ # 30 ]
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Looks like for now I will not be able to confirm the interger settings for the Occussion Smaples. I will have to go further a field to find the correct information. I did try but hit a stone wall for now.

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